Linux kernel turning for mail performance?

[Jeremy Hansen]

Is there any kernel sysctl or otherwise parameters suggested for
performance using qmail on Linux?  Open file handle limits, share memory,
whatever?  I have a goal to send at least 1 million emails in a 
24 hour period from a single machine.

Also, has anyone done any experimentation using 2.3.x kernels and
qmail?  Any feedback on experiences with 2.3.x?

Thanks
-jeremy